The invention relates to a portable compressor transportable over a towing surface where the portable compressor includes a support leg, and more particularly the invention relates to a portable compressor having a support leg where the support leg includes a flexible joint for preventing damage to the support leg when the support leg comes in contact either with the towing surface, or with a stationary object located on the towing surface.
Rigid support legs sometimes referred to as jacks or prop legs are rigidly connected to the frame of a portable compressor and are used to support the front end of the compressor frame before and after the portable compressor frame is disconnected from a tow vehicle. Such support legs are a common feature in portable compressors and are usually provided with means for raising or swinging the support leg out of an extended support position while the compressor is being towed, to prevent the support leg from coming in contact with the towing surface or an object located on the towing surface. Frequently, compressor operators forget to raise or swing the support leg out of the extended support position before towing the compressor and as a result, the clearance between the support leg and the towing surface is not sufficient to prevent the support leg from being damaged by the towing surface or a stationary object on the towing surface.
A conventional portable compressor 10 that includes a prior art support leg 12 is shown in FIG. 1. The support leg is shown in greater detail in FIG. 2. Current portable compressors like the compressor shown in FIG. 1 and identified at 10, generally include a compression module 11 supported by frame 14 equipped with two wheels 15 for transporting the compressor 10 over a towing surface.
The support leg 12 is removably attached to the compressor frame 14 at the front end 16 of the frame by a pin connection 19 or by another conventional connection means. The support leg includes a first tubular member 18 that is removably connected to the frame 14, and a second tubular telescoping member 20 nested within the first tubular member. The first member 18 includes ends 21 and 23. Either wheel 22 shown in FIG. 1 or support pad 24 shown in FIG. 2 may be attached to the end of the second tubular member located outside of first member 18.
A nut 26 or other threaded member is fixed to the end of the second tubular member located in the hollow interior of the first tubular member 18 and threadably receives an elongate threaded member 28 which is rotated by a hand crank 30 operably connected to elongate threaded member 28. The elongate threaded member 28 extends through the second tubular member 20 into the interior of the second tubular member. See FIG. 2. Conventional bearing member 32 located along the threaded member 28 adjacent the hand crank 30, supports rotation of the hand crank. The bearing member may be any suitable bearing well known to one skilled in the art including a thrust bearing or bushing for example.
When the portable compressor 10 is delivered to a job site, the support leg second member 20 is extended to support the front end 16 of the compressor frame 14. The hand crank is rotated in a first direction to cause the nut and member 20 to move in a telescoping manner outward from member 18 along axis 17. The support leg is extended until the support pad or wheel is located on the towing surface.
When use of the portable compressor at the job site is completed, the second member 20 is retracted in a telescoping manner into the member 18 by rotating the hand crank in a second direction to cause the nut and member 20 to translate upward into member 18 along axis 17. The second member is retracted to provide sufficient clearance between the support leg wheel 22 or pad 24 and the towing surface as the compressor is towed to the next job site.
When the clearance between the support leg and towing surface is relatively small, and the support leg comes in contact with both stationary objects on the towing surface or the towing surface itself the support leg is usually damaged beyond repair since the support leg 12 is rigidly connected to the compressor frame 14 and does not include means for preventing damage to the support leg as a result of such contact.
Additionally, the compressor support leg may also be damaged at the job site. After the support leg has been extended, the compressor may roll or otherwise move from a stationary position at the job site and as the compressor moves, the support leg is frequently damaged by contact with the towing surface or an object or curb at the site.
The foregoing illustrates limitations known to exist in present devices and methods. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.